This invention relates to synchronous motors, particularly of the type wherein peripheral teeth on a rotor and magnetized by a permanent magnet move relative to radially projecting teeth on a coaxial electromagnetically energized stator.
Motors of this type are disclosed in U.S. Pat. Nos. 2,105,513, 2,105,514, and 2,589,999. In such motors, cylindrical rotors magnetized by permanent magnets carrying radially-projecting and peripherally spaced rotor teeth extending longitudinally parallel to the rotor axis rotate relative to a coaxial stator whose electrically energized stator poles carry radially-projecting and circularly-spaced stator teeth extending longitudinally parallel to the rotor axis. The magnet fields created at the teeth by the permanent magnet and the electrical signals at the stator poles move the rotor synchronously with the electrical signals. Such motors can stop at predetermined locations in response to applied input signals.
These motors, while suitable for many uses, have the disadvantage of generating undesirable noise and vibration.
An object of this invention is to improve such motors.
Another object of this invention is to reduce the noise and vibration generated by such motors while maintaining their desired characteristics.